The Teen Mom OG cast members' odysseys are ever-changing -- and when Amber, Catelynn, Farrah and Maci are featured in brand-new episodes of the long-running series, their stories will continue to evolve -- and life's getting bigger for these moms!

In order to properly prepare for the return of Teen Mom OG (don't miss it on April 17 and catch a first look above!), MTV will air a catch-up special to get you up to speed on where the girls' tales left off when we last saw them on this network. From major milestones (a proposal, a baby, a wedding and new businesses) to getting honest about their health (seeking treatment and disclosing a difficult diagnosis), the foursome have certainly held nothing back as they invite viewers into their respective worlds. There is plenty of ground to cover -- and we've got you covered.

Don't miss the Teen Mom OG special airing on Monday at 9/8c -- and be sure to catch the MTV mamas when the new season begins on Monday, April 17 at 9/8c!